Add property to ExpandoObject with the same name as a string

Question

Is there a way to add a property to an ExpandoObject with the same name as a string value?

For example, if I have:

string propName = "ProductNumber";
dynamic obj = new System.Dynamic.ExpandoObject();

I can create the property ProductNumber like:

obj.ProductNumber = 123;

But, can I create the property obj.ProductNumber based on the string propName? So, if I don't know what the name of the property will be in advanced, I can create it based on this input. If this is not possible with ExpandoObject, any other areas of C# I should look into?

Solution 1

ExpandoObject implements IDictionary<string, object>:

((IDictionary<string, object>)obj)[propName] = propValue

I don't know off the top of my head whether you can use the indexer syntax with a dynamic reference (i.e., without the cast), but you can certainly try it and find out.

Solution 2

Cast the ExpandoObject to an IDictionary<string,object> to do this:

string propName = "ProductNumber";
dynamic obj = new System.Dynamic.ExpandoObject();
var dict = (IDictionary<string,object>)obj;
dict[propName] = 123;